Machines of the kind referred to above include a vehicle with three or more wheels and one or more rotary tools which are arranged on respective vertically driven drive shafts. The rotary tools rest on the base during the time that the surface thereof is worked. The wheels of the vehicle which can, for example, be three in number are on the surface to be worked during the working procedure and carry the weight of the vehicle. One of the wheels is used to steer the machine with a vertical control shaft. The vehicle carries a motor to drive the cutter head and a control apparatus.
The rotary tool is held by a tool holder which in turn is attached to a vertically positioned rotatable shaft mounted in a bearing housing. The bearing housing is mounted on the vehicle chassis so that it is freely movable with respect to the vehicle in the vertical direction. The pressure of the cutter head on the surface to be worked is adjustable by means of a displacement mechanism or separate loading weights. The weight of the vehicle chassis is carried by the wheels which is in contrast to other known machines wherein the weight is carried by the cutter heads. This weight is so selected that the wheels press against the base with such a load that a displacement of the machine as a consequence of the rotation of the rotary tool is prevented. More specifically, the friction forces between the wheels and the base exceed the action of the torque that is developed by the rotary tool so that the torque developed by the rotary tool is taken up by the machine and not by the operator of the machine.